Question

The total income from the sale of cheeseburgers was what percent greater in 2004 than in 2003?

Answer 1

`\bf \begin{array}c \cline{1-3} year&quantity&price\\ \cline{1-3} 2003&Q&P\\&&\\ 2004&20\%Q+Q&\\&&\\ &(20)/(100)Q+Q&\\&&\\ &1.2Q&\\&&\\ &&10\%P+P\\ &&(10)/(100)P+P\\&&\\ &&1.10P\\ \cline{1-3} &&\\ &(1.2Q)&(1.10P)\\ \cline{1-3} \end{array}\qquad \begin{array}{llll} \stackrel{\textit{revenue for 2003}}{(Q)(P)}\implies QP\\\\ \stackrel{\textit{revenue for 2004}}{(1.2Q)(1.10P)}\implies 1.32QP \end{array}`